diff --git a/web/default/src/features/auth/sign-up/components/sign-up-form.tsx b/web/default/src/features/auth/sign-up/components/sign-up-form.tsx
index b3a5813d..b5ebd0b8 100644
--- a/web/default/src/features/auth/sign-up/components/sign-up-form.tsx
+++ b/web/default/src/features/auth/sign-up/components/sign-up-form.tsx
@@ -155,7 +155,7 @@ export function SignUpForm({
         password: data.password,
         email: data.email || undefined,
         verification_code: verificationCode || undefined,
-        aff: getAffiliateCode(),
+        aff_code: getAffiliateCode(),
         turnstile: turnstileToken,
       })
 
diff --git a/web/default/src/features/auth/types.ts b/web/default/src/features/auth/types.ts
index b429e20c..60aedd97 100644
--- a/web/default/src/features/auth/types.ts
+++ b/web/default/src/features/auth/types.ts
@@ -37,7 +37,7 @@ export interface RegisterPayload {
   password: string
   email?: string
   verification_code?: string
-  aff?: string
+  aff_code?: string
   turnstile?: string
 }